On Dec. 16, 2022 yahoo finance made changes to its web pages. This has caused a number of issues to the SMF Add-in, but it has also caused errors with yFinance python module.
The web site for the SMF Add-In
https://climbermel.github.io/SMF_Add-in/
The GitHub for code changes for SMF Add-In
https://github.com/ClimberMel/SMF_Add-in
The GitHub for yFinance
https://github.com/ranaroussi/yfinance
The PyPi install for yFinance